Drilling apparatus



(No Model-.) 2 Sheets-Sheet 1.

J. F. WILLARD. DRILLING APPARATUS.

N0. 5 4|1,256. Patented June 18,1895.

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' UNITED STATES PATENT Orricn- JACOB F. WILLARD, OF HOWARD, KANSAS.

DRILLING APPARATUS.

SPECIFICATION forming part of Letters Eatent No. 541,256, dated June 18,1 895. Application filed August 6, 1894- 1 Serial No. 519,582. (Nomodel.)

To all whom it may concern.-

Be it known that I, JACOB F. WILLARD, a citizen of the United'States,residingat Howard, in the county of Elk and State of Kansas, haveinvented a new and useful Drilling Apparatus, of which the following isa specification.

My invention relates to a percussion or impact rock drill, and has forits object to provide automatic rotary and longitudinal feed mechanismfor the drill; and furthermore to provide means whereby the drill maybeoperated by hand or foot power, or by any suitable driving or impactmechanism.

Further objects and advantages of this invention will appear in thefollowing description, and the novel features thereof will beparticularly pointed out in the appended claims.

In the drawings, Figure 1 is a view of a drilling mechanism embodying myinvention arrangedin operative position. Fig. 2 is a central sectionalview of the same parallel with the drill, showing the latter in itselevated or retracted position. Fig. 3 is a similar view showing thedrill in its depressed or operating position. Fig. 4 is a sectional Viewof the cylinder with the drill and actuating devices removed. Fig. 5 isa horizontal section on the line 5 5 of Fig. 2, showing the tappet-platein plan. Fig. 6 is a detail view in perspective of the operating-lever.Fig. 7 is a detail view of one of the pawls.

Similar numerals of reference indicate corresponding parts in all thefigures of the drawings.

1 designates a cylinder, which is preferably provided with removableheads 2, having central guide-openings 3, to receive the polygonal shank4 of the rock-drill 5. \Vithin this cylinder, and arranged parallel withits heads, is a reciprocating tappet 6, also provided with aguide-opening 7, to register with the guideopenings in the heads andreceive the shank of the drill. This tappet comprises a plate 8, havingradial arms 9, which are provided at their terminals with antifrictionrollers 10 for a purpose hereinafter explained. Arranged at an intervalfrom and parallel with the plate Sis a disk 11 forming a part of thetappet and carrying a pivoted pawl 12, which operates in conjunctionwith a block 14, by which the of the drill.

plates 8 and 11 are connected to form a clutch for the engagement of theshank of the drill to prevent independent upward movement of the tappetand independent down ward movement The pawl 12 is provided with anactuating spring 1?. The main plate '8 of the tappet carries a lockingpawl 16, similar to the pawl12,and provided with an actnatingspring 17.The clutch-pawl 12 is arranged upon the upper surface of the disk 11 andengages the shank of the drill to enable the latter to derive verticalupward movement from the tappet when the latter is elevated; and thelocking pawl 16 is located at the under side of the main plate 8 tocommunicate downward motion from the tappet to the drill shank when thetappet is depressed. In other words, the pawl 12 is capable of upwardmovement'and isheld from downward movement, while the pawl 16 is capableof downward movement and is held from upward movement, beyond the pointsat which they are firmly engaged with the surfaces of the polygonalshank of the drill. Thus, with said locking and clutch pawls in theirnormal or operative positions, as they are held by their actuatingsprings, the drill shank is locked'against motion in either directionindependently of the tappet.

18 represents a drill actuating or retracting spring which is preferablyspiral in form to enable the coils thereof to fold into a com mon planewhen the spring is compressed by the downward movement of the tappet, as

shown clearly in Fig. 3; and carried by the lower plate 11 of thetappet, and depending below the lower surface thereof, is a trip-pin 19,which fits slidably in a perforation 20 in said plate or disk andengagesat its upper end to the pawl 12, near the free end of the latter,whereby, when the tappet is depressed, as shown in Fig. 3, the trip-pincomes in contact with the lower head of the cylinder and' is elevated,thus disengaging the pawl 12 from the shank of the drill.

In operation a blow upon the end of the drill shank advances the latterand carries the tappet to the lower end of the cylinder, thus causingthe trip-pin to disengage the clutch-pawl from the shank, and allowingthe contracted spring 18 to repress or elevate the tappet; but, as thedisengagement of the pawl 12 from the drill shank is only momentary,owing to the action ofthe spring 13, and

as the said pawl is allowed to resume its normal position in engagementwith the drill shank, as soon as the tappet has been moved a sufficientdistance to remove the trip-pin from contact with the head of thecylinder, the backward movement of the tappet, inde pendent of thedrill-shank, will be checked, and any further movement of the tappet inthe same direction will be communicated to the drill. This momentaryrelease of the clutch-pawl from the drill shank at the limit of theforward movement of the drill, thus causes a change in the relativepositions of the tappet and the drill, such change of positionconsisting in a slight advance of the drill. Thus the drilling operationis advanced slightly at the end of each forward movement.

In the drawings 1 have shown, and in the description I have referred,inmatters of position and direction, to the mechanism as arranged to drillvertically downward, or in the floor, but it will be obvious that it isadapted to operate with equal facility in drilling horizontally, as in abreast-wall, or vertically upward, as in the roof of a cut. Thestep-bystep advancement of the drill being effected by means ofspring-actuated mechanism proceeds in any position of the drill.

The side walls of the cylinder are provided with a continuous or endlessseries of communicating guides, which are preferably constructed asgrooves or channels. 'The'ad vance guides 21 are arrangedlongitudinally, or parallel with the axis of the cylinder, and arespaced apart at regular intervals, and the connecting or return guides23 are arranged at an inclination to the axis of the cylinder andconnect the lower or inner end of one advance guide to the upper orouter end of the adjacent advance guide. Gates 23 are locatedrespectively at the intersections of the advance and return guides, andpreferably consist of plate springs which are disposed to lie across,and'hence close the outlet end of each return and advance guide.

The anti-friction rolls carried by the tappet fit and operate in theseguides and travel therein in the direction indicated by the arrows inFig. 5, whereby the gates which close the outer ends of the guides aredeflected or opened by contact of the arms of the tappet to allow suchparts to pass into the intersecting end of the succeeding guide, butreturn immediately to their normal or closed positions to barreturnthrough the preceding guide and direct; the arm into said succeedingguide. Thus, the drill is reciprocated by successive blows of a sledge,or by other intermittent operating mechanism, and by the return spring,the tappet and drill are rotated regularly and steadily by the arms ofsaid tappet traveling in the guides, said guides preventing backward andcompelling forward movement or rotation. The advance guides 21 arearranged parallel with the axis of the cylining or mouth of the hole inwhich the drillis t operating, the same consisting of pivotal arms 24,provided with spurs 25 to engage the walls of said hole, andadjusting-screws 26, whereby thelower or spurred ends of the holdingarms may be spread or contracted, and thus adjusted to suit the size ofthe opening formed by the drill. It will be understood that when thedrill is forwardly actuated by means of a sledge or by any other forceacting directly upon'the shank of the drill, the locking-pawl 16,carried by the tappet, is unnecessary for the reason that the downwardmovement of the d rillis communicated to the tap pet, and the upwardmovement of the tappet is communicated to the drill by the clutch-pawl12; but when it is desired to operate the drill by footpower, or othermeans acting upon the tappet to advance the drill, said locking-pawl isnecessary in order to communicate the advance movement of the tappet tothe drill. I have shown a foot-operating device in connection with theapparatus, the same consisting of an angle-lever 27, which is fulcrumedupon the casing or cylinder, operates in a slot in the side thereof, andis provided with a bifurl flexible band 29, which travels over aguidepulley 30 and is connected to a foot-lever or treadle 31. r 7

From the above description it will be understood that whether the drillis actuated by impact, as by the use of a sledge or hammer, or by othermeans, such as the foot-lever above described, it will be advanced orfed longitudinally step by step, and at the same time will receive arotary motion which distributes the action of the head of the drill andavoids the necessity of turning the same by hand as intheordinarypractice. It will be understood, furthermore, that variouschanges in the form, pro.portion, and the minor details of constructionmay be resorted to without departing from the principle or sacrificingany of the advantages of this invention. For instance, the dispositionof the parts forming the foot-operating mechanism requires change tosuit the position of the drill, for the reason that the operation of thecam lever will be affected di'iferently by gravity-that is, whendrilling in a roof the spring for elevating the foot lever would not .berequired; or if used, it

would be arranged in the reverse position to that shown in Fig. 1; whilein drilling a breast- IIO hole springs would be arranged on both sides,or both above and below the foot lever.

Having described the invention, what is claimed is 1. In adrill-operating mechanism, the combination of a spring-retracted tappet,a clutch carried by said tappet, and a trip device to disengage theclutch from the drill at the end of the advance stroke, substantially asspecified.

2. The combination with a drill, of a springretracted tappet, aclutch-pawlcarried by. the tappet to engage and prevent independentadvance movement of the drill, a locking pawl carried by the tappet toengage and prevent independent return movement of the drill,

means for imparting an advance movement to the tappet, and a trip deviceto disengage the clutch-pawl at the end of the advance stroke,substantially as specified.

3. The combination with a drill, of a tappet carrying a clutch-pawl toengage and prevent independent advance movement of the drill, a spiralretracting spring arranged to return the tappet after each advancestroke, and a trip-pin arranged to trip the clutchpawl at the end of anadvance stroke, substantially as specified.

4. The combination with a drill, of a tappet carrying aclutch-pawl toengage the drill, a retracting spring for the tappet, and a trippincarried by the tappet, connected to the free end of said clutch-pawl anddepending in position to contact with a stationary object at the end ofeach stroke, substantially as specified.

5. The combination with a drill, of a tappet having parallel platesprovided with radial arms terminating in anti-friction rolls, meanscarried by the tappet for imparting a forward or advance movement to thedrill, a cylinder inclosing said tappet and provided in its walls with acontinuous series of communicating advance and return guides the advanceguides being parallel with the path 45 of the drill and the returnguides being at an inclination to the advance guides and connectingopposite ends of said guides, the antifriction rolls at the terminals ofthe arms of the tappet being arranged to travel in the guides, andspring gates attached to the side walls of said guides adjacent to theirpoints of communication with the preceding guides, respectively, andhaving their free ends ar ranged to close said preceding guides and inalignment with the guides to the walls of which they are secured,whereby the rolls dur ing their advance movement travel toward the freeends of the gates to facilitate passage from one guide to the next,substantially as specified.

6. The combination witha drill, a tappet provided with an actuatingretraction spring, locking and clutch pawls carried by the tappettoengage the drill, and trip devices to disengage the clutch-pawl from thedrill, of an operating lever provided with a bifurcated cam-faced headto engage the upper surface of the tappet, and means to operate saidlever, substantially as specified.

7. The combination with a cylinder or casing, a drill and operatingmechanism therefor, of a holding device comprising curved spring metalarms 24 adjustably connected to the cylinder or casing and provided attheir lower ends with terminal spurs 25 to engage the walls of the holein which the drill is operating, and adjusting devices for said armsconsisting of set-screws 26, substantially as specified.

In testimony that I claim the foregoing as myown I have hereto affixedmy signature in the presence of two witnesses.

- JACOB F. WILLARD. Witnesses:

O. L. MOKESSON, C. W. BOGUE.

